CN107851757B

CN107851757B - Power supply device, power supply system including the same, and battery cell separator

Info

Publication number: CN107851757B
Application number: CN201680044330.8A
Authority: CN
Inventors: 别所寿彦
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 2015-07-30
Filing date: 2016-07-11
Publication date: 2020-11-13
Anticipated expiration: 2036-07-11
Also published as: JP6752790B2; US10418671B2; JPWO2017017914A1; WO2017017914A1; CN107851757A; US20180138560A1

Abstract

A power supply device that, in order to be able to insulate the surfaces of battery cells at low cost, simplify the insulating structure between the battery cells, and maintain the battery cells in an insulated state from a fastening member, includes: a plurality of battery cells (1), each battery cell (1) having a square outer shape; a separator (2) that is connected to each of the plurality of battery cells (1) and that at least partially covers the surface of the battery cell (1); and a fastening member that fastens a battery laminate formed by stacking a plurality of battery cells (1) covered with a separator (2) in a state in which the main surfaces thereof face each other. The separator (2) is composed of an insulating member that can elastically deform, and includes a main plate section (20) that covers the main surfaces of the battery cells (1) that are arranged to face each other; a box-shaped covering section that is provided at the bottom of the main plate section (20) on the first surface (20A) side and that covers the bottom surface of the battery cell (1) by inserting the bottom surface of the battery cell (1) into the box-shaped covering section; and a corner covering section (22) that is provided on the top section of the main plate section (20) on the first surface (20A) side and covers the corner section of the top surface section of the battery cell (1).

Description

Power supply device, power supply system including the same, and battery cell separator

Technical Field

The present invention relates to a power supply device in which a plurality of battery cells are stacked, a power supply system including the power supply device, and a separator for insulating the battery cells used in the power supply device.

Background

A power supply device using a secondary battery is used for applications such as a driving power supply of a vehicle. As shown in the exploded perspective view of fig. 17, the power supply device includes: a plurality of battery cells 91 whose outer shape is formed in a square shape; a plurality of separators 92; a pair of connecting rods 95; a pair of end plates 94. The separators 92 are respectively interposed between the adjacent battery cells 91. The battery stack 99 is formed by alternately stacking a plurality of battery cells 91 and a plurality of separators 92. The battery laminate 99 is covered with end plates 94 at both end surfaces of the battery cells 91 in the lamination direction. Each tie bar 95 extends in the stacking direction of the battery cells 91 and is fixed to the end plates 94 located at both ends of the battery stack 99. A typical battery cell includes a conductive outer can, positive and negative electrode plates, and an electrolyte. Since the positive and negative electrode plates and the electrolytic solution are sealed in the conductive outer can, the outer can has a potential. Therefore, in order to prevent undesired conduction, corrosion of the outer can, and the like due to dew condensation and the like between adjacent secondary batteries, it is necessary to insulate the surface of the outer can. For example, since the bottom surface side of the battery cell is a portion into which dew-condensed water droplets flow, it is necessary to insulate the bottom surfaces of the exterior can from each other. In order to maintain the battery stack in a connected state, which is obtained by stacking the battery cells, a fastening member, such as a tie bar, which is obtained by bending a metal plate may be used.

As the insulating structure, for example, a structure in which an insulating sheet made of resin such as PET is covered on the surface of an outer can is known (for example, see patent documents 1 and 2). Specifically, a shrink tube capable of covering the surface of the outer can in a close contact state by thermal shrinkage is used as the insulating sheet. However, in the structure in which the outer can is covered with the insulating sheet, each battery cell must be covered with the insulating sheet in advance. Therefore, the above structure has problems such as low workability and high manufacturing cost.

In addition, in a conventional power supply device in which a plurality of battery cells are stacked, since a separator is interposed between adjacent battery cells when the battery cells are stacked, the battery cells and the separator need to be alternately positioned and stacked, which causes a problem that assembly becomes complicated and efficient production is not possible.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-033668

Patent document 2: japanese patent laid-open No. 2008-166191

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made to solve the above-mentioned problems of the prior art. An object of the present invention is to provide a power supply device, a power supply system including the power supply device, and a battery cell separator, which are capable of insulating the surface of a battery cell at low cost.

Another object of the present invention is to provide a power supply device, a power supply system including the power supply device, and a battery cell separator, which can simplify an insulation structure between battery cells, maintain an insulation state between the battery cells and a fastening member, and effectively prevent a short circuit due to dew condensation or the like.

Another object of the present invention is to provide a power supply device, a power supply system including the power supply device, and a battery cell separator, which can simplify assembly and can be efficiently produced when a plurality of battery cells are stacked in a manufacturing process of the power supply device.

Means for solving the problems and effects of the invention

According to an aspect of the present invention, a power supply device includes: a plurality of battery cells 1, each battery cell 1 having a thickness smaller than the width of the main surface 1X and a square outer shape;

separators

2, 62 coupled to each of the plurality of battery cells 1, and at least partially covering the surface of the battery cell 1; and a fastening member 3 that fastens a battery laminate 9 in which a plurality of battery cells 1 covered with the

separators

2, 62 are laminated in a posture in which the main surfaces 1X face each other. The

separators

2, 62 are made of an insulating member that can elastically deform, and include: a main plate portion 20 that covers the main surface 1X of the battery cell 1 disposed to face each other; a box-shaped covering portion 21 provided at the bottom portion of the main plate portion 20 on the first surface 20A side, and covering the bottom surface portion 1T of the battery cell 1 by inserting the bottom surface portion 1T of the battery cell 1 into the box-shaped covering portion 21; and a corner covering portion 22 provided at the top of the first surface 20A side of the main plate portion 20 and covering the corner portion 1S of the top surface portion of the battery cell 1.

According to the above configuration, since the bottom surface portion of the battery cell is covered with the box-shaped covering portion of the separator without using a covering material such as a shrink tube, there is obtained an advantage that a short circuit due to dew condensation water can be effectively prevented even in a state where moisture such as dew condensation is accumulated on the bottom surface. In addition, the bottom surface portion of the battery cell is inserted into the box-shaped covering portion of the separator, and the corner portion of the top surface portion of the battery cell is covered and held by the corner covering portion, whereby the battery cell can be easily arranged at a predetermined position of the separator, and the surface of the battery cell is covered and insulated by the separator.

In the power supply device of the present invention, the bottom surface portion 1T of the battery cell 1 is inserted into the box-shaped covering portion 21 of the

separator

2, 62, the corner portion 1S of the top surface portion of the battery cell 1 is covered with the corner covering portion 22, the

battery cell assembly

10, 60 in which the

separator

2, 62 is attached to a predetermined position of the battery cell 1 is formed, and the battery stack 9 can be formed by stacking a plurality of

battery cell assemblies

10, 60.

According to the above configuration, the bottom surface portion of the battery cell is inserted into the box-shaped covering portion of the separator, and both corner portions of the top surface portion of the battery cell are covered and held by the corner covering portions, whereby a battery cell assembly in which the separator is attached to a predetermined position of the battery cell can be formed easily and reliably. Therefore, in the manufacturing process, the battery cell assembly in which the separators are attached to the battery cells can be stored, transported, and assembled in units, and the battery cells having a non-stretchable structure can be used, and the operation can be performed safely and securely. In particular, in the assembly step, a battery stack is formed by stacking a plurality of battery cell assemblies each having a separator mounted on a battery cell, so that the assembly work can be simplified and the productivity can be improved.

In the power supply device of the present invention, the spacer 2 may further include a side wall 23, the side wall 23 may form a side surface of the box-shaped covering portion 21 and a side surface of the corner covering portion 22 on the side surface of the first surface 20A of the main plate portion 20, and a notch 24 may be formed in the middle of the side wall 23.

According to the above configuration, the side wall is provided on the side surface of the first surface side of the main plate portion of the separator, the side surface of the battery cell connected to the separator is covered and insulated by the side wall, and the cutout is provided in the intermediate portion of the side wall, whereby the main plate portion of the separator can be easily bent, and the battery cell can be easily provided to the separator. In this separator, for example, the battery cell can be easily and easily placed at a predetermined position of the separator by inserting the bottom surface portion of the battery cell into the box-shaped covering portion in a state where the cutout of the side wall of the main plate portion is bent to the opposite side of the first surface, and then guiding the corner portion of the top surface portion of the battery cell to the corner covering portion while restoring the main plate portion to the original posture.

In the power supply device of the present invention, the separator 2 may have a first air supply duct 30A formed in the first surface 20A of the main body panel 20, and the first air supply duct 30A may be configured to form an air passage 8 between the battery cells 1 stacked on the first surface 20A side of the main body panel 20 and the main body panel 20, and to allow both end openings of the first air supply duct 30A to communicate with the notch 24.

According to the above configuration, the ventilation passage for cooling the battery cells stacked on the first surface side of the main body plate portion is provided in the first surface side of the main body plate portion so as to communicate with the notch of the side wall, whereby the separator can be easily elastically deformed while ensuring the transport path of the cooling gas.

In the power supply device of the present invention, the separator 2 may have a second air duct 30B formed on a second surface 20B of the main body panel 20, which is a surface opposite to the first surface 20A, the second air duct 30B may be configured to form an air passage 8 between the battery cells 1 stacked on the second surface 20B side of the main body panel 20 and the main body panel 20, and both end openings of the second air duct 30B may be opened along the side walls 23.

According to the above configuration, the ventilation passage for cooling the battery cells stacked on the second surface side of the main body plate portion is provided along the side wall on the second surface side of the main body plate portion, whereby the ventilation passage for cooling the battery cells can be efficiently ensured.

In the power supply device of the present invention, the main plate portion 20 may include a reverse extension side wall 25, the reverse extension side wall 25 may extend toward the second surface 20B along the notch 24, and the reverse extension side wall 25 may be formed in a shape to be fitted into the notch 24 of the spacer 2 disposed adjacent to the reverse extension side wall.

According to the above configuration, the separators connected to the battery cells can be mechanically connected to each other by fitting the reverse extension side walls into the notches in a state where the separators are stacked. In addition, this can cover substantially the entire side surface of the battery cell.

The power supply device of the invention can be such that the side wall 23 comprises a vertical wall 31 in the longitudinal direction and the opposite extension side wall 25 comprises a vertical wall 32 in the longitudinal direction.

According to the above configuration, the creepage distance between the adjacent battery cells is extended by the vertical wall provided on the side wall and the reverse extension side wall, so that occurrence of an undesired short circuit due to dew condensation or the like can be effectively prevented, and insulation between the battery cells can be improved.

In the power supply device of the present invention, the fastening member 3 may include: a pair of end plates 4, the pair of end plates 4 being disposed on both end surfaces of the cell stack 9; the tie bar 5 has both ends connected to the pair of end plates 4, the tie bar 5 includes a side panel portion 5X, the side panel portion 5X covers the side surface of the battery stack 9, the side panel portion 5X is provided with an air blowing opening 5D, the air blowing opening 5D faces the opening portion of the ventilation duct 8, and

vertical walls

31 and 32 formed on the side wall 23 and the reverse extension side wall 25 are disposed at the air blowing opening 5D.

According to the above configuration, the vertical walls provided on the side wall and the reverse extension side wall are disposed at the air blowing openings provided in the tie bars disposed on the side surfaces of the cell stack, whereby the creeping distance between the cell and the tie bars is extended, and thus, an undesired short circuit between the cell and the tie bars due to dew condensation or the like can be effectively prevented. Further, by disposing the vertical wall in the air blowing opening provided in the connecting rod, the cooling air can be made to flow into the opening portion of the ventilation passage along the vertical wall, and the air blowing path to the ventilation passage can be secured.

In the power supply device of the present invention, the side wall 23 and the reverse extension side wall 25 may include two rows of

vertical walls

31 and 32 at positions opposite to each other, and the two rows of

vertical walls

31 and 32 opposite to each other may form a continuous vertical groove 34. The tie bar 5 may include a tie bar 5F, the tie bar 5F may reinforce the side panel portion 5X in which the air blowing openings 5D are opened, the tie bar 5F may form a plurality of air blowing openings 5D in the side panel portion 5X, and the tie bar 5F may be inserted into the vertical groove 34.

According to the above configuration, the side plate in which the air blowing opening is opened is reinforced by the connecting rod, and the connecting rod is inserted into the vertical groove formed by the vertical walls formed in the side wall and the reverse extension side wall, whereby an undesirable short circuit between the battery cell and the connecting rod due to dew condensation or the like can be effectively prevented. Further, by disposing the connecting rod in the vertical groove, the cooling gas forcibly fed can be prevented from being affected by the connecting rod, and effective cooling can be achieved.

The power supply device of the present invention may further include an insulating cover film 63, the cover film 63 covering a part of the battery cell 1, and the cover film 63 extending at least from the surface of the battery cell 1 covered with the box-shaped covering portion 21 to the surface of the battery cell 1 covered with the corner covering portion 22 in the battery cell 1 covered with the separator 62.

According to the above configuration, the bottom surface portion of the battery cell is covered by the box-shaped covering portion of the separator, and the corner portion of the top surface portion of the battery cell is covered by the corner covering portion, and the battery cell is covered by the insulating covering film from the surface of the battery cell covered by the box-shaped covering portion to the surface of the battery cell covered by the corner covering portion, so that the region from the bottom surface portion to the top surface portion of the battery cell can be covered in an insulating state, and a person or metal can be prevented from directly contacting the surface of the battery cell, and undesired current conduction can be reliably prevented.

The power supply device of the present invention can be disposed in a state in which both side surfaces of the battery stack 9 face in the vertical direction.

According to the above configuration, since the bottom surface portion of the battery cell is covered with the box-shaped covering portion of the separator and the corner portion of the top surface portion of the battery cell is covered with the corner covering portion, even in a state in which both side surfaces of the battery stack are arranged in a horizontal posture in the vertical direction, moisture generated by dew condensation or the like can be made to flow down along the inner surfaces of the box-shaped covering portion and the corner covering portion, and short circuit due to dew condensation water can be effectively prevented. In particular, in the structure in which the side wall and the reversely extending side wall are provided in the main plate portion of the separator, and the vertical wall is provided in the side wall and the reversely extending side wall, the creepage distance of dew condensation water or the like flowing down along the inner surface of the box-shaped covering portion or the corner covering portion is extended by the vertical wall disposed on the lower surface side of the power supply device disposed in the horizontal posture, so that occurrence of an undesired short circuit due to dew condensation or the like can be effectively prevented, and the insulation between the battery cells can be improved. Further, since the top surface of the battery cell is disposed in the left-right direction, restrictions such as vertical load can be reduced.

The power supply system of the present invention may include a plurality of any one of the power supply devices 100, and may include at least one pair of the power supply devices 100, each of the power supply devices 100 being disposed in a posture in which both side surfaces of the battery stack 9 face in the vertical direction, and the pair of the power supply devices 100 being disposed in a posture in which the bottom surfaces of the battery stack 9 face each other, and the top surfaces of the battery cells 1 being disposed in the opposite directions to each other in the horizontal direction.

According to the above configuration, the pair of power supply devices are disposed in a posture in which both side surfaces of the battery stack face in the vertical direction and are laterally inclined, and the bottom surface of the battery stack faces each other, so that the pair of power supply devices can be disposed in a space-saving manner, the top surfaces of the battery cells face in the left-right direction and are opposed to each other, and the electrode terminals of the battery cells can be efficiently wired.

The separator of the present invention can be used in a power supply device in which a plurality of battery cells 1 having a thickness smaller than the width of the main surface X1 and a rectangular outer shape are stacked, and is configured to insulate the surfaces of the battery cells 1, and includes: a main plate portion 20 that covers the main surface 1X of the battery cell 1 disposed to face each other; a box-shaped covering portion 21 provided at the bottom portion of the main plate portion 20 on the first surface 20A side, and covering the bottom surface portion 1T of the battery cell 1 by inserting the bottom surface portion 1T of the battery cell 1 into the box-shaped covering portion 21; and a corner covering portion 22 provided on the top portion of the main plate portion 20 on the first surface 20A side and covering the corner portion 1S of the top surface portion of the battery cell 1, the separator being made of an insulating member that is elastically deformable.

According to the above configuration, since the bottom surface of the battery cell is covered with the box-shaped covering portion of the separator without using a covering material such as a shrink tube, there is obtained an advantage that a short circuit due to dew condensation water can be effectively prevented even in a state where moisture such as dew condensation is accumulated on the bottom surface.

Drawings

Fig. 1 is a perspective view of a power supply device according to an embodiment of the present invention.

Fig. 2 is an exploded perspective view of the power supply device shown in fig. 1.

Fig. 3 is a partially enlarged III-III sectional view of the power supply device shown in fig. 1.

Fig. 4 is a partially enlarged sectional view IV-IV of the power supply apparatus shown in fig. 1.

Fig. 5 is an exploded perspective view illustrating a stacked structure of the battery cell assembly.

Fig. 6 is an exploded perspective view of the battery module.

Fig. 7 is a rear perspective view of the battery cell assembly shown in fig. 6.

Fig. 8 is a bottom perspective view of the separator shown in fig. 6.

Fig. 9 is a bottom perspective view of the separator shown in fig. 7.

Fig. 10 is a perspective view showing a state in which a separator is inserted into a battery cell.

Fig. 11 is an exploded perspective view illustrating a stacked state of the battery cell assembly shown in fig. 5.

Fig. 12 is an enlarged perspective view showing a side surface of the battery device shown in fig. 1.

Fig. 13 is an exploded perspective view showing another example of the power module.

Fig. 14 is a perspective view of the battery cell and the cover film shown in fig. 13.

Fig. 15 is a perspective view of a power supply system according to an embodiment of the present invention.

Fig. 16 is a cut-away perspective view of the power supply system shown in fig. 15.

Fig. 17 is an exploded perspective view of a conventional power supply device.

Detailed Description

Fig. 1 to 4 show a power supply device 100 according to an embodiment of the present invention. The power supply device 100 shown in fig. 1 to 4 includes: a plurality of battery cells 1 whose outer shape is formed in a square shape; a separator 2 that is connected to each of the plurality of battery cells 1 and at least partially covers the surface of the battery cell 1; and a fastening member 3 that fastens a battery laminate 9 in which a plurality of battery cells 1 covered with the separator 2 are laminated in a posture in which the main surfaces 1X face each other. As shown in fig. 5, the power supply device shown in fig. 1 to 4 includes a battery cell assembly 10 in which a separator 2 is attached to a battery cell 1, and a battery stack 9 is formed by stacking a plurality of the battery cell assemblies 10.

(Battery unit 1)

The battery cell 1 is a rectangular battery, and has a main surface 1X having a wide width, which is formed in a quadrangular shape, and a thickness smaller than the width of the main surface 1X. The battery unit 1 is a chargeable and dischargeable secondary battery, and is a lithium ion secondary battery. However, in the power supply device of the present invention, the battery cell is not particularly limited to the lithium ion secondary battery, and all batteries that can be charged and discharged, for example, a nonaqueous electrolyte secondary battery other than the lithium ion secondary battery, a nickel hydride battery cell, and the like can be used.

The battery cell 1 is a member in which an electrode body obtained by laminating positive and negative electrode plates is housed in an outer can 1a, and is hermetically sealed by filling an electrolyte. As shown in fig. 6, the outer can 1a is formed in a rectangular tube shape having a closed bottom, and an upper opening is hermetically closed by a metal plate sealing plate 1 b. The outer can 1a is manufactured by drawing a metal plate made of aluminum, aluminum alloy, or the like. The sealing plate 1b is made of a metal plate such as aluminum or aluminum alloy, as in the outer can 1 a. The sealing plate 1b is inserted into the opening of the outer can 1a, and a laser beam is irradiated to the boundary between the outer periphery of the sealing plate 1b and the inner periphery of the outer can 1a to laser-weld the sealing plate 1b to the outer can 1a and hermetically fix the same.

As shown in fig. 6, in the battery unit 1, positive and negative electrode terminals 13 are fixed to both ends of a sealing plate 1b in a protruding manner. The positive and negative electrode terminals 13 are connected to built-in positive and negative electrode plates (not shown), respectively. The position of the electrode terminal 13 fixed to the top surface of the battery cell 1 is bilaterally symmetrical between the positive electrode and the negative electrode. As a result, the battery cells 1 are stacked upside down, and the adjacent positive and negative electrodes are connected to the electrode terminal 13 of the negative electrode by the metal plate bus bar 17, thereby enabling series connection. The power supply device in which the battery cells 1 are connected in series can increase the output voltage and increase the output. However, the power supply device can also connect the battery cells in parallel and in series.

As shown in fig. 5, a battery cell 1 as a prismatic battery constitutes a battery cell assembly 10 by mounting a separator 2. The plurality of battery cell assemblies 10 are stacked in the thickness direction of the battery cells 1 to form a battery stack 9. In the present specification, the vertical direction of the battery unit 1 refers to a direction specified in fig. 6. The side surfaces 1Y of the battery cell 1 are narrow surfaces arranged on both sides of the battery stack 9 in a state where the battery stack 9 is formed by stacking a plurality of battery cell assemblies 10 in a posture where the main surfaces 1X as the wide surfaces face each other.

(spacer 2)

The separator 2 is made of an insulating member, and is connected to each battery cell 1 as shown in fig. 3 to 9, and covers and insulates a part of the surface of the battery cell 1. The separator 2 insulates the battery cells 1 stacked on each other, and maintains the adjacent battery cells 1 at a fixed interval. The separator 2 is molded from an insulating material such as plastic. Particularly, the separator 2 is made of a soft material having elasticity, a plastic material such as PP, or silicon or the like.

As shown in fig. 3 to 9, the separator 2 includes a main plate portion 20 that covers the main surface 1X of the battery cell 1 disposed to face each other; a box-shaped covering portion 21 provided at the bottom of the main plate portion 20 on the first surface 20A side, and inserted into and covering the bottom surface portion 1T of the battery cell 1; and a corner covering portion 22 provided on the top of the first surface 20A side of the main plate portion 20 and covering the corner portion 1S of the top surface portion of the battery cell 1. In this separator 2, the main surface 1X on one side of the battery cell 1 constituting one battery cell assembly 10 is covered with the main plate portion 20, the bottom surface portion 1T of the battery cell 1 is held by the box-shaped covering portion 21, and the corner portion 1S of the top surface portion of the battery cell 1 is held by the corner covering portion 22, whereby the battery cell 1 is held at a predetermined position.

(Main body plate 20)

As shown in fig. 6 and 7, the main plate portion 20 is formed in a plate shape having substantially the same size and shape as the main surface 1X of the battery cell 1. In the main plate portion 20, the side where the battery cells 1 constituting the battery cell assembly 10 are arranged is a first surface 20A, a box-shaped covering portion 21 is provided at the bottom portion on the first surface 20A side, and corner covering portions 22 are provided at both corner portions of the top portion. The surface of the main plate portion 20 opposite to the first surface 20A is a second surface 20B, and the second surface 20B is brought into contact with the main surface 1X of the battery cell 1 constituting the adjacent stacked battery cell assembly 10. That is, the main plate portion 20 covers the first main surface 1Xa of the battery cell 1 provided in the separator 2 and constituting the battery cell assembly 10 by abutting the first main surface 20A, and covers the second main surface 1Xb of the battery cell 1 constituting the adjacently stacked battery cell assembly 10 by abutting the second main surface 20B.

(Box-shaped covering part 21)

The box-shaped covering portion 21 is formed in a box shape into which the bottom surface portion of the battery cell 1 can be inserted. The box-shaped covering portion 21 shown in fig. 6 to 9 is formed in a box shape having an upper opening, and the entire bottom surface of the bottom surface portion of the rectangular battery cell 1 can be inserted and covered. The box-shaped covering portion 21 includes: a bottom surface covering portion 21A formed along a lower end edge of the main plate portion 20 and protruding toward the first surface 20A side; a front surface covering portion 21B rising upward from a front end edge of the bottom surface covering portion 21A; and a side surface covering portion 21C formed by connecting both side edges of the main plate portion 20, the bottom surface covering portion 21A, and the front surface covering portion 21B. The box-shaped covering portion 21 is provided integrally with the main plate portion 20.

In this box-shaped covering portion 21, the bottom surface of the battery cell 1 inserted along the first surface 20A of the body plate portion 20 is covered by the bottom surface covering portion 21A, the bottom portion of the second main surface 1Xb of the battery cell 1 is covered by the front surface covering portion 21B, and the bottom portions of the both side surfaces 1Y are covered by the side surface covering portions 21C. The box-shaped covering portion 21 having this structure covers the entire bottom surface portion 1T of the battery cell 1 inserted therein without a gap. Therefore, even if water droplets such as dew condensation water flow into the bottom surface side of the battery cell 1, the entire bottom surface portion 1T of the battery cell 1 is covered with the box-shaped covering portion 21, and therefore, short-circuiting due to the water droplets can be reliably prevented.

In the box-shaped covering portion 21 shown in fig. 3 and 6, a step protrusion 21D protruding toward the inner surface side is formed at both end portions of the inner surface of the bottom surface covering portion 21A, and a gap 29 is formed between the bottom surface of the battery cell 1 and the inner surface of the bottom surface covering portion 21A in a state where the bottom surface of the battery cell 1 is in contact with the step protrusion 21D. This structure allows water droplets that have flowed into the box-shaped covering portion 21 to flow into the gap 29 and temporarily accumulate therein, thereby preventing the water droplets from flowing out to the outside.

(corner covering part 22)

The corner covering portion 22 is configured to guide the corner portion 1S of the top surface portion of the rectangular battery cell 1 and to lock the corner portion 1S. The corner covering portion 22 shown in fig. 6 to 9 is formed in a recessed shape in which one side surface is removed from the opening of the box shape so that the corner portion 1S of the rectangular battery cell 1 can be fitted. The corner covering portion 22 includes: a top surface covering portion 22A formed at both side edges of an upper end edge of the main plate portion 20 and protruding toward the first surface 20A side; a front cover portion 22B extending downward from a front end edge of the top cover portion 22A; and a side surface covering portion 22C formed by connecting side edges of the main plate portion 20, the top surface covering portion 22A, and the front surface covering portion 22B. The corner covering portion 22 is provided integrally with the main panel portion 20.

In the corner covering portion 22, the bottom surface portion 1T is covered with both end portions of the top surface (sealing plate 1B) of the battery cell 1 inserted into the box-shaped covering portion 21 by the top surface covering portion 22A, both side portions of the top portion of the second main surface 1Xb of the battery cell 1 are covered with the front surface covering portion 22B, and both side surface covering portions 1Y are covered with the side surface covering portions 22C. In the corner covering portion 22 having this configuration, when the corner portion 1S of the battery cell 1 is guided, the elastically deformed front covering portion 22B is turned up outward (see arrow C in fig. 10), whereby the opening of the recess is enlarged, and the corner portion 1S of the battery cell 1 is easily inserted. In a state where the corner portions 1S of the battery cell 1 are guided to the corner covering portions 22, the inner surfaces of the top surface covering portion 22A, the front surface covering portion 22B, and the side surface covering portion 22C are brought into contact with the surface of the corner portions 1S of the battery cell 1, whereby the corner portions 1S of the battery cell 1 can be positioned.

In the corner covering portion 22 shown in fig. 4 and 8, a positioning convex portion 22D is provided so as to protrude from the inner surface of the top surface covering portion 22A. In the separator 2, the positioning projections 22D are brought into contact with both side portions of the top surface of the battery cell 1, and the battery cell 1 can be arranged at a predetermined position of the separator 2.

(side wall 23)

The separator 2 includes a side wall 23 that forms a side surface of the box-shaped covering portion 21 and a side surface of the corner covering portion 22 on the side surface of the first surface 20A of the main plate portion 20. The side wall 23 shown in fig. 5 to 9 includes a lower side wall 23A including a side surface of the box-shaped covering portion 21; and an upper side wall 23B including a side surface of the corner covering portion 22. The side wall 23 in the figure is formed with a notch 24 in the middle, and the lower side wall 23A and the upper side wall 23B are vertically divided by the notch 24. The lower side wall 23A includes a side surface covering portion 21C of the box-shaped covering portion 21, a vertical side wall 26 extending upward from the side surface covering portion 21C, and the bottom of the side surface 1Y of the battery cell 1 facing each other is covered with the side surface covering portion 21C and the vertical side wall 26. The upper side wall 23B includes a side surface covering portion 22C of the corner covering portion 22, a vertical side wall 26 extending downward from the side surface covering portion 22C, and the top of the side surface 1Y of the battery cell 1 facing the side surface covering portion 22C and the vertical side wall 26 is covered. The center portion of the side surface 1Y of the battery cell 1 is not covered with the side wall 23, and is exposed to the outside in a state where the separator 2 is mounted, as shown in fig. 5.

Of the vertical side walls 26 of the lower side wall 23A and the vertical side walls 26 of the upper side wall 23B, one side edge is connected to the main plate portion 20, the other end edge is located before the second main surface 1Xb of the battery cell 1, and the lateral width of the vertical side wall 26 is smaller than the thickness of the battery cell 1. That is, in the lower side wall 23A and the upper side wall 23B shown in the figure, the lateral width of the vertical side wall 26 is narrower than the lateral widths of the side

surface covering portions

21C, 22C, the exposed cut portion 27 is provided at the side edge of the vertical side wall 26 on the second main surface 1Xb side, and the corner portion of the outer can 1a of the battery cell 1 is exposed at this portion. The exposure cut portions 27 of the longitudinal side walls 26 are provided with both end opening portions of the ventilation passage 8 formed between the main body plate portions 20 of the partitioning member 2 disposed oppositely, the details of which will be described later. In other words, in the side wall 23, the air blowing path to the air passage 8 is secured by exposing the corner portion of the outer can 1a along the exposed cut portion 27 of the vertical side wall 26.

In the separator 2, the side wall 23 is provided on the side surface on the first surface 20A side of the main plate portion 20, so that the side surface 1Y of the battery cell 1 to which the separator 2 is attached is covered and insulated by the side wall 23, and the notch 24 is provided in the intermediate portion of the side wall 23, so that the main plate portion 20 is easily bent by the notch 24 and is easily provided in the battery cell 1. As shown in fig. 10, in this separator 2, the upper portion of the main plate portion 20 is bent toward the second surface 20B at the notch 24 of the side wall 23 (see arrow a), so that the bottom surface portion 1T of the battery cell 1 can be easily inserted into the inside of the box-shaped covering portion 21 (see arrow B), and the corner portion 1S of the battery cell 1 can be guided toward the inside of the corner covering portion 22 while the upper portion of the bent main plate portion 20 is restored to the original posture, so that the battery cell 1 can be disposed at a predetermined position of the separator 2. In particular, when the corner portion 1S of the battery cell 1 is guided to the corner covering portion 22, the elastically deformed front covering portion 22B is turned up outward (see arrow C) to enlarge the opening of the recess, and the corner portion 1S of the battery cell 1 can be easily inserted.

In the side wall 23 shown in the figure, convex portions 28 protruding outward are formed on the surfaces of the side

surface covering portions

21C and 22C. The distal end surface of the projection 28 is formed in a flat shape, and is brought into contact with the inner surface of the tie bar 5 disposed on the side surface of the battery stack 9, whereby the positioning thereof can be performed. By bringing the inner surface of the tie bar 5 into contact with the distal end surface of the projection 28, the distance between the spacer 2 and the tie bar 5 can be maintained at a predetermined distance.

(reverse extension side wall)

The spacer 2 includes a reverse extension side wall 25 extending toward the second surface 20B of the main plate 20 along the notch 24 of the side wall 23. The reverse extension side wall 25 is plate-shaped protruding toward the second surface 20B of the main plate portion 20, and is formed in a shape to be fitted into the notch 24 of the separator 2 disposed adjacent thereto, as shown in fig. 5. The reversely extending side walls 25 shown in fig. 7 and 9 are configured such that stepped recesses 25A are formed along upper and lower ends of one surface side facing the side surface 1Y of the battery cell 1, and the leading edges of the vertical side walls 26 of the facing separators 2 are guided to the stepped recesses 25A and can be fitted to each other. The reversely extending side walls 25 are formed in a wrap-around structure (ラップ structure, Japanese) in which the front end edges of the longitudinal side walls 26 and the stepped recesses 25A are stacked on each other, whereby dew condensation water and the like can be effectively prevented from passing through the portions. The inner surface of the side wall 23 and the inner surface of the opposite extension side wall 25 are disposed on the same plane, so that they can be disposed along the side surface 1Y of the battery cell 1.

As described above, the separators 2 including the reverse extension side walls 25 can be mechanically coupled to each other by fitting the opposite separators into the notches 24 using the reverse extension side walls 25 in a state where the battery cell assemblies 10 adjacent to each other are stacked. Therefore, in the step of stacking a plurality of battery cell assemblies 10, the battery cell assemblies 10 can be quickly stacked in the correct posture without being misaligned. Further, since the exposed portion of the battery cell 1 generated in the notch 24 portion of the separator 2 is covered by the reverse extension side wall 25 of the separator 2 of the adjacent battery cell assembly 10, it is possible to cover substantially the entire side surface 1Y of the battery cell 1. Accordingly, the both side surfaces of the cell laminate 9 are substantially entirely covered with the side wall 23 and the reverse extension side wall 25 of the separator 2, and thereby the surface of the outer can 1a having a potential can be prevented from being exposed to the outside, and safety can be improved.

(ventilation path 8)

In the separator 2, a groove-like recess is provided on the surface of the main plate portion 20 so as to convey the cooling gas along the surface of the battery cell 1 in a state of being in close contact with the surface of the battery cell 1, and an air passage 8 is formed between the opposing surfaces of the battery cells. The separator 2 shown in fig. 3 to 4, 7, and 8 has air blowing grooves 30 extending to both side edges on a surface facing the battery cell 1, and a gap formed between the air blowing grooves 30 and the main surface 1X of the battery cell 1 is defined as an air passage 8. As shown in fig. 1 and 6 to 9, the ventilation path 8 is provided in the horizontal direction so as to be open on the left and right side surfaces of the battery stack 9.

In the separator 2 shown in fig. 3, 6 to 9, and 11, the air supply grooves 30 are provided in a plurality of rows on both surfaces of the main plate portion 20, and the ventilation passages 8 are formed on both surfaces of the main plate portion 20. The ventilation passages 8 formed on both surfaces of the main plate portion 20 are linear and arranged in a plurality of rows parallel to each other. This structure has an advantage that battery cells 1 arranged to face each other on both sides can be efficiently cooled by ventilation passages 8 formed on both sides of main plate portion 20. However, the separator may be provided with the air supply duct only on one side, and the ventilation passage may be provided between the battery cell and the main plate portion. The separator may be provided with an air passage only in a central portion thereof facing the central portion of the battery cell, for example.

In the separator 2 shown in fig. 6, 8, and 11, the first air duct 30A is formed in the first surface 20A of the main plate portion 20, and the air passage 8 is formed between the battery cells 1 stacked on the first surface 20A side of the main plate portion 20 and the main plate portion 20 by the first air duct 30A. The partition 2 in the figure has two rows of first air supply grooves 30A formed in the center portion of the first surface 20A of the main plate portion 20, and the openings at both ends of the first air supply grooves 30A communicate with the notches 24. In this configuration, the ventilation passage 8 for cooling the battery cells 1 stacked on the first surface 20A side of the main plate portion 20 is provided so as to communicate with the notches 24 of the side walls 23, whereby a cooling gas transport path can be secured on the left and right side surfaces of the battery stack 9. Further, the amount of protrusion of the reverse extension side wall 25 disposed in a state of being fitted to the notch 24 toward the second surface 20B is adjusted so as to avoid the both end openings of the first air blowing duct 30A from being closed.

In the separator 2 shown in fig. 7, 9, and 11, the second air supply duct 30B is formed in the second surface 20B of the main body panel 20, and the air passage 8 is formed between the battery cells 1 stacked on the second surface 20B side of the main body panel 20 and the main body panel 20 by the second air supply duct 30B. In the spacer 2 shown in the figure, a row of second air supply grooves 30B is formed in each of the upper and lower sides of the second surface 20B of the main plate portion 20. In the separator 2, a second air blowing groove 30B is formed along the upper and lower sides of the ridge protruding toward the second surface 20B on the back surface of the first air blowing groove 30A formed on the first surface 20A, and both ends of the second air blowing groove 30B are opened along the side wall 23. In the partition 2 shown in the figure, the openings at both ends of the second air blowing groove 30B are arranged along the exposed cut portions 27 provided in the side walls 23 of the partition 2 stacked to face each other. This allows the openings at both ends of the second air blowing grooves 30B to be exposed to the outside, thereby ensuring a cooling gas supply path on the left and right side surfaces of the battery stack 9.

As shown in fig. 4, the ventilation passages 8 formed on both surfaces of the main plate portion 20 are disposed so as to face the air blowing openings 5D opened in the tie bars 5 disposed on the side surfaces of the battery stack 9 for the purpose of conveying the cooling gas. The cooling gas forcibly fed to the battery unit 1 flows into the ventilation passage 8 from the air blowing opening 5D formed in the one connecting rod 5 to cool the battery unit, passes through the ventilation passage 8, and then flows out to the outside from the air blowing opening 5D formed in the other connecting rod 5.

(vertical walls 31, 32)

The separator 2 includes

vertical walls

31 and 32 along the longitudinal direction of the side wall 23 disposed on the side surface 1Y of the battery cell 1 and the opposite extension side wall 25. The side wall 23 shown in fig. 5 to 9 is provided with two rows of vertical walls 31 protruding outward along both side edges of the vertical side wall 26 extending from the

side covering portions

21C, 22C. The side walls 23 are formed such that two rows of vertical walls 31 are parallel to each other. The vertical wall 31 formed along the exposure cutout 27 of the two rows of vertical walls 31 is provided with a bent portion 31A along a boundary portion with the side

surface covering portions

21C, 22C, extending a creeping distance of the inner surface side and the outer surface side of the side wall 23 in the entire region where the cutout 27 is exposed. In the bent portion 31A in the figure, a rib 33 parallel to the side wall 23 is provided along the inner surface for reinforcement. Further, since the vertical walls 31 formed along the exposed cutouts 27 of the side walls 23 are erected along the openings at both ends of the second air supply duct 30B formed between the battery cells 1 arranged to face each other, the cooling air fed from the outside can efficiently flow into the ventilation duct 8 along the vertical walls 31.

In addition, in the reverse extension side wall 25 shown in fig. 5 to 9, two rows of vertical walls 32 are arranged in parallel in the longitudinal direction. As shown in fig. 5, two rows of vertical walls 32 formed on the reverse extension sidewalls 25 are formed: the battery cell assemblies 10 adjacent to each other are stacked such that the reverse extension side walls 25 of one battery cell assembly 10 are fitted into the notches 24 of the other battery cell assembly 10, and are positioned on extension lines of two rows of vertical walls 32 formed on the side walls 23. Since the vertical wall 32 formed along the front end edge of the reverse extension side wall 25 is erected along the openings on both sides of the first air blowing duct 30A, the cooling air fed from the outside can efficiently flow into the ventilation duct 8 along the vertical wall 32.

As shown in fig. 12, the

vertical walls

31 and 32 formed on the side wall 23 and the opposite extension side wall 25 are disposed in the air blowing opening 5D, and the air blowing opening 5D is opened in the side panel portion 5X of the tie bar 5 disposed on the side surface of the cell stack 9. This extends the creepage distance between battery cell 1 and connecting rod 5, and prevents short-circuiting between battery cell 1 and connecting rod 5 due to dew condensation or the like. With the

vertical walls

31, 32 shown in the drawing, the amount of projection is adjusted so that the leading edge thereof is located on substantially the same plane as the outer side surface of the connecting rod 5. However, the vertical wall may have a front end edge protruding beyond the outer surface of the connecting rod. The configuration in which the

vertical walls

31 and 32 are disposed in the air blowing opening 5D of the connecting rod 5 enables smooth flow of the cooling air into the air passage 8 that opens along the

vertical walls

31 and 32.

In addition, among the side wall 23 and the reverse extension side wall 25 shown in fig. 12, two rows of

vertical walls

31 and 32 disposed at positions facing each other form a continuous vertical groove 34. In the power supply device shown in the figure, the tie bar 5 disposed on the side surface of the battery stack 9 includes a tie bar 5F connected to the air blowing opening 5D, and the tie bar 5F is inserted into the vertical groove 34. In this configuration, the coupling rod 5F of the coupling rod 5 is inserted into the vertical groove 34 formed in the

vertical walls

31 and 32 provided in the side wall 23 and the opposite extension side wall 25, whereby short-circuiting between the battery cell 1 and the coupling rod 5F due to dew condensation or the like can be effectively prevented.

(positioning connection part 40)

In the separator 2 shown in the figure, a positioning connection portion 40 protruding in the stacking direction of the battery cells 1 is provided along the outer periphery of the main plate portion 20, and the battery cell assemblies 10 stacked adjacent to each other can be connected at a predetermined position. The positioning joint portion 40 shown in the figure includes a bottom surface joint portion 41 which positions both corner portions of the bottom surface side of the partitioning member 2; and corner connecting portions 42 for positioning both corners of the top surface side of the separator 2.

(basal surface connecting part 41)

The bottom surface connecting portion 41 is formed along the lower end edge of the main plate portion 20 so as to protrude toward the second surface 20B side. The bottom surface connecting portion 41 is a plate-like member extending in the stacking direction of the battery cells 1, and is provided on the entire bottom surface of the box-shaped covering portion 21. The bottom surface connecting portion 41 is stacked on the bottom surface of the box-shaped covering portion 21 of the adjacently stacked battery cell assembly 10, and is connected to the outside of the box-shaped covering portion 21 of the opposing separator 2. The bottom surface connecting portion 41 shown in the figure has a structure in which: both side portions are erected along both corner portions of the box-shaped covering portion 21, and the box-shaped covering portion 21 is positioned and connected in the left-right direction by the erected portions.

As described above, by forming the bottom surface portion of the box-shaped covering portion 21 into the double-walled structure together with the bottom surface coupling portion 41, even if any one of the box-shaped covering portion 21 and the bottom surface coupling portion 41 is damaged due to deterioration with time, vibration, or the like, conduction with the tie bar 5 due to dew condensation water or the like can be effectively prevented. However, the bottom surface connecting portion does not necessarily need to cover the entire bottom surface from the viewpoint of positioning and connecting the adjacent separators, and may be configured to cover only both side portions of the bottom surface. In this case, it is preferable that the bottom surface connecting portion is formed to face a portion abutting against the lower end bent portion of the tie bar.

The bottom surface connecting portion 41 shown in fig. 3 to 7 includes a convex strip 43 which abuts against and is positioned at the lower end bent portion 5A of the tie bar 5. In the bottom surface connecting portion 41 shown in the figure, a convex strip 43 extending in the stacking direction of the battery cells 1 is provided at a portion facing the lower end bent portion 5A of the tie bar 5. In the state where the plurality of separators 2 are stacked and connected, the convex strips 43 of the separators 2 adjacent to each other are linearly connected to form a row of connecting convex strips extending in the extending direction of the lower end bent portion 5A of the tie bar 5. The convex strip 43 can position the inner surface of the lower end bent portion 5A in contact with the tip end surface of the convex strip 43 in a state where the tie bar 5 is disposed on the side surface of the cell stack 9. The bottom surface connecting portion 41 shown in fig. 8 and 9 has a structure in which: a notch 44 is provided at a tip end portion facing the convex strip 43, and the convex strip 43 of the facing separator 2 can be fitted into the notch 44 and positioned. The convex strip 43 shown in fig. 8 and 9 is provided across a part of the box-shaped covering portion 21 from the bottom surface connecting portion 41, and is connected to the notch portion 44 of the bottom surface connecting portion 41 in a fitting structure on the bottom surface of the box-shaped covering portion 21.

(Angle joint 42)

The corner connecting portion 42 is formed along both corners on the top surface side of the main plate portion 20 so as to protrude toward the second surface 20B side. The corner connecting portion 42 is formed in a plate shape having a substantially L-shaped vertical cross section, and extends in the stacking direction of the battery cells 1. The corner connecting portion 42 is laminated on the upper end portion of the side surface covering portion 22C along the top surface covering portion 22A of the corner covering portion 22, and is connected to the outside of the corner covering portion 22. The corner connecting portion 42 having a substantially L-shaped vertical section is positioned vertically by the horizontal portion and positioned horizontally by the vertical portion, and is connected to the corner covering portion 22.

The corner connecting portion 42 shown in fig. 8 and 9 has the following structure: the fitting notch 46 is provided at the front end of the horizontal portion, and the fitting convex portions 47 formed on the surfaces of the top surface covering portions 22A of the facing separators 2 can be fitted and positioned with each other.

The corner connecting portion 42 shown in fig. 3 to 7 includes a convex strip 45 which abuts against and is positioned at the upper end bent portion 5B of the link 5. The corner connecting portion 42 shown in the figure is provided with a convex strip 45 extending in the stacking direction of the battery cells 1 on the upper surface of the horizontal portion at a portion facing the upper end bent portion 5B of the connecting rod 5. In a state where a plurality of separators 2 are stacked and connected, the convex strips 45 of the separators 2 adjacent to each other are linearly connected to form a row of connecting convex strips extending in the extending direction of the upper end bent portion 5B of the tie bar 5. In the separator 2, the inner surface of the upper end bent portion 5B of the tie bar 5 can be positioned in contact with the distal end surface of the convex strip 45 in a state where the tie bar 5 is disposed on the side surface of the cell stack 9.

In the separator 2 shown in fig. 4 to 9, rising walls are provided on both side portions of the top surface and project upward along the side edges of the corner covering portion 22 and the corner connecting portion 42. The standing wall 48 separates and insulates the electrode terminal 13 provided on the top surface of the battery cell 1 from the front end edge of the upper end bent portion 5B of the connection rod 5. The structure in which the rising wall 48 is provided between the leading end edge of the tie bar 5 and the upper surface of the battery cell 1 as described above extends the creepage distance of this portion, and can effectively prevent an unintended short circuit.

As shown in fig. 11, in the above positioning and connecting portion 40, in a state where the battery cell assemblies 10 adjacent to each other are stacked and connected, the bottom surface connecting portion 41 is connected along the bottom surface of the box-shaped covering portion 21, and the corner connecting portion 42 is connected along the outer periphery of the corner covering portion 22, and the separators 2 stacked adjacent to each other are positioned and connected in the vertical direction, the left direction, and the right direction. In the bottom surface connecting portion 41 connected along the bottom surface of the box-shaped covering portion 21, the convex strips 43 of the facing separator 2 are fitted into and positioned in the notch portion 44 formed in the front end portion. In the corner connecting portion 42 connected along the outer periphery of the corner covering portion 22, fitting convex portions 47 of the separators 2 facing each other are fitted into fitting notch portions 46 formed in the front end portion of the horizontal portion and positioned.

(Battery cell unit 10)

As shown in fig. 5, the above separator 2 is attached to the battery cell 1 to constitute a battery cell assembly 10. The battery cell assembly 10 has such a structure: the surface of the battery cell 1 is partially covered with the separator 2, and in a state where the battery stack 9 is configured by stacking a plurality of battery cell assemblies 10, substantially the entire region of the battery cell 1 except for a part of the top surface, for example, a part of the electrode terminal 13 can be covered. This structure can reliably prevent direct contact between a person or metal and the surface of the battery cell 1 having a potential, and prevent undesired current supply. Further, by covering substantially the entire surface of the battery cell 1, even if dew condensation water is generated, it is possible to effectively prevent the surface of the battery cell 1 from coming into contact with an exterior member, for example, the tie bar 5 and causing electric current to flow therethrough.

In addition, since the battery cell assembly 10 is configured by the battery cells 1 and the separators 2, the battery cell assembly 10 can be handled in units in the manufacturing process, and thus, the workability can be improved. For example, in a conventional power supply device, a battery laminate is formed by alternately laminating a plurality of battery cells and separators interposed therebetween, and the battery laminate is fastened in a state where the battery laminate is pressed from both ends. In contrast, in the present invention, since the separator 2 is attached to the battery cell 1 to form the battery cell assembly 10 and the plurality of battery cell assemblies 10 are stacked on each other to form the battery stack 9, the operation can be simplified and the productivity can be improved. Further, operations such as storage, transportation, and assembly can be performed in a state where the separator 2 is attached to the battery cell 1, and safety can be improved.

(other embodiments)

Further, the separator can also be formed in the structure shown in fig. 13. Here, the separator 62 of the embodiment shown in fig. 13 omits the side wall 23 and the opposite extension side wall 25 covering the side surface 1Y of the battery cell 1, as compared with the above-described separator 2 shown in fig. 6. That is, the spacer 62 may have the same configuration as the above-described spacer 2 shown in fig. 6, with respect to the components other than the side wall 23 and the reverse extension side wall 25. Accordingly, in fig. 13, the same components as those in the embodiment of fig. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

In the separator 62 shown in fig. 13, a box-shaped covering portion 21 is provided on the bottom portion on the first surface 20A side of the main plate portion 20 covering the main surface 1X of the battery cell 1 disposed to face each other, and the box-shaped covering portion is insertable into and covers the bottom surface portion 1T of the battery cell 1; and a corner covering portion 22 that covers the corner 1S of the top surface portion of the battery cell 1 is provided on the top portion of the main body panel portion 20 on the first surface 20A side. In the separator 62, a side wall and a reverse extension side wall are not provided in a portion facing the middle portion of the side surface 1Y of the battery cell 1, and the side surface side of the battery cell 1 is exposed. In the spacer 62 shown in the figure, both side edges of the main plate portion 20 are formed as cut edges.

In the spacer 62, since the side wall and the reverse extension side wall are not formed on the side surface of the main plate portion 20, the mold for manufacturing the spacer 62 can be simplified and mass production can be performed at low cost. In addition, in the separator 62 not provided with the side wall, the main plate portion 20 can be freely bent at the intermediate portion, and can be easily provided to the battery cell 1. Similarly to the separator 2 shown in fig. 10, the separator 62 can easily insert the bottom surface portion 1T of the battery cell 1 into the inside of the box-shaped covering portion 21 by bending or bending the upper portion of the main plate portion 20 to the side opposite to the first surface 20A, and can set the battery cell 1 at a predetermined position of the separator 62 by guiding the corner portion 1S of the battery cell 1 to the inside of the corner covering portion 22 while restoring the upper portion of the bent or bent main plate portion 20 to the original posture.

The main body plate 20 shown in fig. 13 is provided with a duct 30 that forms an air passage with the opposing battery cell surface. In the spacer 62 shown in fig. 13, two rows of first air blowing grooves 30A are formed in the central portion of the first surface 20A of the main plate portion 20, and one row of second air blowing grooves 30B are formed in the upper and lower portions of the first air blowing grooves 30A on the opposite side. However, the separator can also be: the main plate portion has a concave-convex shape in a cross-sectional view, and the first air supply grooves and the second air supply grooves are alternately formed on both surfaces of the main plate portion.

The separator 62 in fig. 13 has an open side surface, and the outer peripheral surface of the battery cell 1 provided thereon is covered with an insulating cover film 63, thereby preventing the side surface of the separator 62 from being exposed to the outside. In the battery unit 1 shown in fig. 13, the cover films 63 are attached to the upper and lower middle portions of the square cylindrical outer can 1A. The cover film 63 is, for example, a silicon film, and is formed in a cylindrical shape along the outer peripheral surface of the outer can 1a as shown in fig. 14. The cover film 63 is covered in close contact with the surface of the outer can 1a of the battery cell 1, and the middle portion of the outer peripheral surface of the battery cell 1 is covered in an insulating state.

The cover film 63 prevents the outer case 1a of the battery cell 1 from being exposed to the outside from the side surface of the separator 62. Therefore, the cover film 63 shown in fig. 13 has a length that can cover the side surface 1Y of the battery cell 1 in the portion not covered by the side surface covering portion 21C of the box-shaped covering portion 21 and the side surface covering portion 22C of the corner covering portion 22. In other words, in the battery cell 1 covered with the separator 62, the cover film 63 extends at least from the surface of the battery cell 1 covered with the box-shaped covering portion 21 to the surface of the battery cell 1 covered with the corner covering portion 22. As described above, by providing the cover film 63 on the battery cell 1, the structure of the separator 62 can be simplified and the separator can be manufactured at low cost, and the portion exposed from the surface of the separator 62 can be reliably insulated.

Here, the structure in which the surface of the battery cell 1 is covered with the covering film 63 increases the manufacturing cost as compared with the structure in which the surface of the battery cell 1 is not covered with a film or the like. However, since the cover film 63 shown in the figure does not cover the entire battery cell including the bottom of the outer can, as in the case of the conventional shrink tube, but only covers the middle portion of the outer can 1a, it is not necessary to closely adhere the entire heat-shrinkable complicated manufacturing process to the surface of the battery cell, as in the case of the conventional shrink tube, and the process of covering the battery cell 1 with the film is simplified, and the bottom of the battery cell 1 is covered with the separator 62, thereby reliably insulating the battery cell. The cover film 63 covering only the middle portion of the outer can 1a can be covered in a close-fitting state by winding a band-shaped film around the outer peripheral surface of the battery cell 1, for example, without being formed in a cylindrical shape and being brought into close-fitting by heat shrinkage or the like. That is, the cover film 63 covers only the middle portion of the outer can without covering the bottom surface portion of the battery cell that is difficult to cover with the conventional shrink tube, thereby simplifying the manufacturing process and reducing the manufacturing cost.

The above separator 62 is also attached to the battery cell 1 covered with the covering film 63, and constitutes the battery cell assembly 60. In this battery cell assembly 60, the main surface 1X on one side of the battery cell 1 is covered with the main plate portion 20 of the separator 62, the bottom surface portion 1T of the battery cell 1 is covered with the box-shaped covering portion 21, and the corner portion 1S of the top surface portion is covered with the corner covering portion 22. The other principal surface 1X and side surface 1Y of the battery cell 1, which is the surface of the battery cell 1 not covered with the separator 62, are covered with the cover film 63. Therefore, in the battery cell module 60, since the entire surface of the battery cell 1 other than the top surface portion is covered in an insulated state, safety during operations such as storage, transportation, and assembly can be improved.

In a state where a plurality of battery cell modules are stacked to form a battery stack, the main plate portion 20 is interposed between adjacent battery cells 1 to insulate them, and the outer case 1a of the battery cell 1 is covered with the covering film 63 at a portion exposed from the side surface. Thus, the electrode terminal 13 is formed so as to cover substantially the entire region except the portion. Therefore, direct contact between a person or metal and the surface of the battery cell 1 having a potential can be reliably prevented, and undesired current conduction can be prevented. Further, by covering substantially the entire surface of the battery cell 1 with the cover film 63 and the separator 62, even if dew condensation water occurs, it is possible to effectively prevent the surface of the battery cell 1 from coming into contact with an exterior member, for example, the tie bar 5 and supplying electricity.

(Battery laminate 9)

As shown in fig. 2 to 5, in the battery laminate 9, a plurality of battery cell assemblies 10 each formed by covering the surface of a battery cell 1 with a separator 2 are laminated in a state where the main surfaces 1X of the battery cells 1 face each other. In the battery stack 9 shown in fig. 2, the intermediate bracket 6 is interposed therebetween. In this configuration, the intermediate portion of the battery stack 9 is reinforced by the intermediate bracket 6, whereby there is obtained an advantage that rigidity can be maintained even when the number of stacked battery cells 1 is increased. However, the battery laminate does not necessarily need to have an intermediate bracket interposed therebetween, and the intermediate bracket may be omitted.

(fastening means 3)

As shown in fig. 1 and 2, a battery stack 9 formed by stacking a plurality of battery cell assemblies 10 is fastened together in the stacking direction by a fastening member 3. The fastening member 3 includes: end plates 4 disposed on both end surfaces of the cell stack 9 in the stacking direction; and tie bars 5, which are formed by fixing both ends to the end plates 4 and fixing the stacked battery cells 1 in a pressurized state. In the battery stack 9, the pair of end plates 4 disposed on both end surfaces thereof are connected to both ends of the tie bar 5, and the intermediate bracket 6 is fixed to an intermediate portion of the tie bar 5, and the stacked battery cells 1 are pressed and fixed in a direction orthogonal to the main surface 1X. However, the fastening member is not particularly limited to the end plate and the connecting rod. The fastening member may have any other structure for fastening the cell laminate in the stacking direction.

(end plate 3)

A pair of end plates 4 is disposed on both end surfaces of the cell stack 9, and the cell stack 9 is fastened by the pair of end plates 4. The end plates 4 have substantially the same outer shape as the battery cells 1 or slightly larger outer shape than the battery cells, and the battery stack 9 is fixed under pressure to form a rectangular plate without deformation. The end plate 4 is made of a material that exerts sufficient strength, for example, metal. However, it can also be: the end plate is made of resin, or is formed by reinforcing the resin end plate with a member made of metal. In the power supply device shown in fig. 1 to 3, the end plate 4 is a laminate of two

metal plates

4A and 4B. The end plate 4 made of metal is laminated on the cell laminate 9 via an end separator 12 as an insulating material.

(connecting rod 5)

As shown in fig. 1 and 2, the tie bars 5 are disposed on the side surfaces of the cell stack 9 having the end plates 4 stacked on both ends thereof, and the cell stack 9 is fastened by fixing both ends to the pair of end plates 4. The connecting rod 5 is manufactured by stamping a metal plate. The tie rod 5 can be made of a metal plate such as iron, and is preferably made of a steel plate. The tie bar 5 in the figure includes a side panel portion 5X disposed on a side surface of the cell stack 9; and fixing portions 5C disposed on the outer end surface of the end plate 4 at both ends of the side plate portion 5X. The side panel portion 5X has an outer shape substantially the same as, and more precisely slightly larger than, the outer shape of the side surface of the battery stack 9. The fixing portion 5C is fixed to the outer end surface of the end plate 4 by a fastening screw 19. Although the tie bar 5 in fig. 1 to 3 is fixed to the end plate 4 by the fastening screw 19, the end portion of the tie bar may be bent inward to be connected to the end plate, or the end portion may be caulked to be connected to the end plate.

As shown in fig. 1, 2, and 4, the connecting rod 5 includes: an upper end bent portion 5B disposed at a side edge portion on the top surface side of the cell laminate 9; and a lower end bent portion 5A disposed at a side edge portion on the bottom surface side of the cell laminate 9. The cell laminate 9 is disposed between the upper-end bent portion 5B and the lower-end bent portion 5A. In the illustrated tie bar 5, an upper edge portion of the side panel portion 5X is bent inward at a right angle to form an upper end bent portion 5B, and a lower edge portion is bent inward at a right angle to form a lower end bent portion 5A. The tie bar 5 is formed in a shape of japanese kana コ in a cross section intersecting the longitudinal direction by bending the upper and lower end edges of the side panel portion 5X, thereby improving rigidity.

The tie bar 5 is provided with an air blowing opening 5D in the side panel portion 5X except for the outer peripheral edge portion, and is formed in a shape capable of passing through the side panel portion 5X and conveying the cooling gas. In the connecting rod 5 in the figure, an air blowing opening 5D is provided substantially over the entire side panel portion 5X. In the tie bar 5, a rectangular peripheral plate portion 5E is provided on the outer peripheral edge of the side plate portion 5X, and an air blowing opening 5D is provided inside the peripheral plate portion 5E. In the side panel portion 5X of fig. 2, the rectangular peripheral plate portions 5E are vertically connected by a plurality of rows of connecting rods 5F, and the peripheral plate portions 5E are reinforced by the connecting rods 5F. In the tie bar 5 in the figure, the plurality of rows of tie bars 5F vertically connecting the peripheral plate sections 5E provide air blowing openings 5D divided into a plurality of areas inside the peripheral plate sections 5E. The plurality of rows of connecting rods 5F are arranged in parallel with each other in a spaced manner in the stacking direction of the battery stack 9. The power supply device shown in fig. 11 is configured such that the connecting rod 5F of the connecting rod 5 is guided to the inside of the vertical groove 34 formed by the

vertical walls

31, 32 of the partition 2. This effectively prevents a short circuit between the coupling rod 5F of the coupling rod 5 and the battery unit 1.

In the tie bar 5 described above, in a state in which the side panel portions 5X are disposed on the side surfaces of the cell stack 9, the peripheral plate portion 5E is disposed outside the side wall 23 of the separator 2, the lower end bent portion 5A is disposed on the lower surface of the bottom surface connecting portion 41 of the separator 2, and the upper end bent portion 5B is disposed on the upper surface of the corner connecting portion 42 of the separator 2. In the tie bar 5, the inner surface of the peripheral plate portion 5E abuts and is positioned on the convex portion formed on the side wall 23, the inner surface of the upper end bent portion 5B abuts and is positioned on the convex portion formed on the bottom surface connecting portion 41, and the inner surface of the upper end bent portion 5B abuts and is positioned on the convex portion formed on the corner connecting portion 42.

(sealing member 11)

As shown in fig. 2 and 4, in the power supply device, a seal 11 is disposed between the tie bar 5 and the cell stack 9. The sealing material 11 is in the form of a sheet, and can be produced by cutting a single sheet of resin after vacuum forming, or by forming the sheet into a predetermined three-dimensional shape by a method such as injection molding of a thermoplastic resin. The sheet-like seal 11 shown in fig. 2 and 4 is formed in a shape having: a plane part 11A closely attached to the inner surface of the tie bar 5 in a surface contact state; and a hollow elastic protruding portion 11B protruding from the flat surface portion 11A toward the surface of the battery stack 9 and extending so as to surround the entire air blowing opening 5D of the tie bar 5. In the sheet-like seal 11, the flat surface portion 11A is brought into close contact with the inner surface of the tie bar 5, and the elastic protrusion 11B is elastically brought into close contact with the surface of the cell stack 9, thereby preventing leakage of the cooling gas between the tie bar 5 and the cell stack 9.

The sheet-like seal 11 has a flat surface portion 11A disposed on the inner surface of the peripheral plate portion 5E, the lower end bent portion 5A, and the upper end bent portion 5B, and elastically presses an elastic protruding portion 11B disposed opposite to the peripheral plate portion 5E against the surface of the battery stack 9, thereby closing the gap between the tie bar 5 and the battery stack 9, that is, the gap between the peripheral plate portion 5E and the separator 2, and preventing leakage of the cooling gas. As shown in the enlarged sectional view of fig. 3, the sheet-like seal 11 is formed by connecting a flat surface portion 11A of an elastically deformable resin sheet to both sides of an elastic protrusion 11B having a groove shape with a U-shaped cross section.

(end spacer 12)

In the power supply device 100 shown in the figure, end separators 12 having insulating properties are disposed between the end plates 4 and the battery cells 1 disposed inside and between the intermediate bracket 6 and the battery cells 1 disposed on both sides of the battery stack 9 at both ends and in the middle. In this structure, the battery cells 1 having the outer can 1a made of metal and the end plates 4 made of metal can be stacked with end spacers 12 therebetween in an insulating manner. As shown in fig. 2 and 3, the end separator 12 is disposed between the cell stack 9 and the end plate 4, and insulates the metal end plate 4 from the battery cell 1.

The end separator 12 disposed on the second main surface 1Xb side of the battery cell 1 is provided with a reverse extension side wall 25 projecting so as to fit into the notch 24 of the separator 2 facing thereto, similarly to the above-described separator 2. This allows the notch 24 of the battery cell assembly 10, whose second main surface 1Xb faces the end plate 4 or the intermediate bracket 6, to be covered without being exposed. The end separator 12 disposed on the second main surface 1Xb side of the battery cell 1 is further provided with a second air supply duct 30B so as to form the air passage 8 with the opposing battery cell 1.

(bus bar 7)

In the plurality of battery cells 1 constituting the battery stack 9, the positive and negative electrode terminals 13 are connected in series with each other via the bus bar 7. The power supply device in which a plurality of battery cells 1 are connected in series can increase the output voltage. However, the power supply device may be configured to connect the battery cells in parallel to increase the current capacity.

(blast duct 51)

In the power supply device 100, in order to forcibly feed the cooling gas to the air passage 8 provided between the battery cell 1 and the separator 2, as shown in fig. 1, a pair of air blowing ducts 51 are provided on both sides, and the forced air blowing mechanism 52 is connected to the air blowing ducts 51. In the power supply device 100, the cooling gas is forcibly fed from the air duct 51 to the air passage 8 to cool the battery unit 1. However, in the power supply device 100, the heating gas may be forcibly fed from the air duct 51 to the air passage 8 to heat the battery unit 1.

The air supply duct 51 includes an inflow duct 51A and a discharge duct 51B. The inflow duct 51A and the discharge duct 51B are provided on opposite sides of each other, and the cooling gas is sent from the inflow duct 51A to the ventilation path 8 and from the ventilation path 8 to the discharge duct 51B, thereby cooling the battery unit 1. A plurality of ventilation passages 8 are connected in parallel to the inflow duct 51A and the discharge duct 51B. Accordingly, the cooling gas sent to the inflow duct 51A is branched and sent through the plurality of ventilation passages 8, and is sent from the inflow duct 51A to the discharge duct 51B. In the power supply device 10 of fig. 1, the inflow duct 51A and the discharge duct 51B are provided on both sides, and therefore the ventilation passage 8 is provided so as to extend in the horizontal direction. The cooling gas is sent in the horizontal direction through the ventilation path 8, and cools the battery unit 1. The shape of the air duct is not necessarily limited to the shape illustrated in fig. 1, and the air duct may be provided in a direction parallel to the air passage 8.

(forced air blowing mechanism 52)

The forced air blowing mechanism 52 includes a fan rotated by a motor, and the fan is connected to the air blowing duct 51. In the power supply device 100, for example, the forced air blowing mechanism 52 is connected to the inflow duct 51A, and the cooling gas is forcibly fed from the forced air blowing mechanism 52 to the inflow duct 51A. In the power supply device 100, the cooling gas is sent in the flow path of the forced air blowing mechanism 52 → the inflow duct 51A → the air passage 8 → the discharge duct 51B, thereby cooling the battery unit 1. However, the forced draft fan may be connected to the discharge duct. The forced draft fan forcibly sucks in the cooling gas from the exhaust duct and exhausts the cooling gas. Thus, in the power supply device, the cooling gas is sent in the flow of the inflow duct → the ventilation path → the discharge duct → the forced draft fan, thereby cooling the battery unit.

(Power supply system)

Fig. 15 shows an example in which the power supply device 100 shown in fig. 1 is disposed in a posture in which both side surfaces of the battery stack 9 face in the vertical direction. Fig. 15 shows a power supply system including a pair of power supply devices 100. In the power supply system shown in fig. 15, each power supply device 100 is arranged in a posture that is laterally reversed from the posture shown in fig. 1, and the top surface on which the positive and negative electrode terminals 13 of the battery unit 1 are provided faces in the left-right direction. In the power supply system, the bottom surfaces of the pair of power supply devices 100 are arranged in an opposing posture, and the top surfaces of the battery stacks 9 are connected in a posture in which the top surfaces face in the left-right direction.

In the power supply system in which the power supply device 100 is disposed in this posture, since both side surfaces of the battery stack 9 are disposed in a posture facing the vertical direction, as shown in fig. 16, the side wall 23 of the separator 2 disposed to face the side surface 1Y of each battery cell 1 is disposed on the lower surface of the power supply device 100 shown in fig. 15. The side wall 23 includes a vertical wall 31 extending in the longitudinal direction, and the vertical wall 31 is disposed in a state of being exposed downward from the air blowing opening 5D of the connecting rod 5. The power supply device 100 is configured such that dew condensation water generated on the surface of the battery cell 1 flows down to the side surface 1Y of the battery cell 1 located on the lower surface side. At this time, on the side surface 1Y of the battery cell 1 located on the lower surface side, since the corner portion on the bottom surface side of the outer can 1a is covered with the box-shaped covering portion 21 and the corner portion 1S on the sealing plate 1b side is covered with the corner covering portion 22, water droplets are prevented from flowing down from the above portion and from directly contacting the tie bar 5. Further, since the side walls 23 provided on the side surfaces of the box-shaped covering portion 21 and the corner covering portions 22 extend toward the middle portion of the battery cell 1, the dew condensation water flows down along the vertical walls 31 formed continuously with the side walls 23 as indicated by arrows in fig. 16. Therefore, the creepage distance can be extended, and the insulation can be improved. In the side wall 23 in the figure, the rib 33 is formed at the upper and lower middle portions of the bent portion 31A provided at the boundary between the side

surface covering portions

21C and 22C and the vertical side wall 26, and therefore the creeping distance is further extended by the rib 33.

In the above power supply system, in order to forcibly feed the cooling gas to the air passage 8 provided between the battery cell 1 and the separator 2, as shown in fig. 15, a pair of air blowing ducts 51 are provided above and below the pair of power supply devices 100 connected at the bottom surfaces, and the forced air blowing mechanism 52 is connected to the air blowing ducts 51. This power supply system also forcibly supplies cooling gas from the air supply duct 51 to the air passage 8 to cool the battery unit 1. In the power supply system shown in the figure, the inlet duct 51A is disposed above the two rows of power supply devices 100, and the outlet duct 51B is disposed below. In this structure, air is blown from above to below in a plurality of ventilation passages 8 formed between the battery cell 1 and the separator 2 and arranged vertically, thereby cooling the battery cell 1. Therefore, dew condensation water or the like generated by dew condensation or the like can be quickly flowed down along the ventilation passage 8 and discharged. That is, in the power supply system having this configuration, the discharge duct 51B disposed below can also serve as a drainage duct for dew condensation water and the like. However, in the power supply system, the inflow duct may be connected to a lower portion of the power supply device, and the discharge duct may be disposed at an upper portion.

Fig. 15 shows an example of a power supply system in which the power supply devices 100 are arranged in a posture in which the posture is horizontal from the posture shown in fig. 1 and the top surface of the battery unit 1 is oriented in the left-right direction, and the pair of power supply devices 100 are arranged in a posture in which the bottom surfaces of the power supply devices face each other, but although not shown, a power supply system including a plurality of power supply devices in the posture shown in fig. 1 may be arranged in a posture in which the power supply devices are arranged in two left-right rows in parallel, or in a posture in which the power supply devices are arranged in two upper and lower rows in parallel.

The power supply device and the power supply system described above can be used in various applications such as a power supply mounted in an electric vehicle such as a hybrid vehicle or an electric vehicle and supplying power to a travel motor, a power supply storing generated power of natural energy such as solar power generation or wind power generation, or a power supply storing midnight power, and can be used particularly as a power supply suitable for applications of high power and large current.

The embodiments and examples of the present invention have been described above with reference to the drawings. However, the above-described embodiments and examples are intended to be illustrative for embodying the technical idea of the present invention, and the present invention is not limited to the above-described embodiments. In addition, the present specification does not limit the components shown in the claims to the components of the embodiments at all. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are merely illustrative, and the scope of the present invention is not limited thereto unless otherwise specified. In addition, the sizes, positional relationships, and the like of the components shown in the drawings may be exaggerated for convenience of explanation. In the above description, the same names and reference numerals denote the same or similar members, and detailed description thereof is omitted as appropriate. Each element constituting the present invention may be a system in which a plurality of elements are constituted by the same component and one component is used as a plurality of elements, or conversely, may be realized by sharing the function of one component among a plurality of components.

Industrial applicability

The battery system of the present invention is most suitable for use in a power supply device that supplies electric power to a motor of a vehicle that requires large electric power, and in a power storage device that stores natural energy and midnight electric power.

Description of the reference numerals

100 power supply device, 1 battery cell, 1X main surface, 1Xa first main surface, 1Xb second main surface, 1Y side surface, 1S corner portion, 1T bottom surface portion, 1A external can, 1B sealing plate, 2 separator, 3 fastening member, 4 end plate, 4A metal plate, 4B metal plate, 5 connecting rod, 5X side surface portion, 5A lower end bent portion, 5B upper end bent portion, 5C fixing portion, 5D air blowing opening, 5E peripheral edge plate portion, 5F connecting rod, 6 intermediate bracket, 7 bus bar, 8 air passage, 9 battery stack, 10 battery cell module, 11 seal, 11A plane portion, 11B elastic projection portion, 12 end separator, 13 electrode terminal, 19 fastening screw, 20 body plate portion, 21 box-shaped covering portion, 21A bottom surface covering portion, 21B front surface covering portion, 21C side surface covering portion, 21D stepped projection portion, 22 corner covering portion, 1B bottom surface covering portion, 1B side surface, 1Y side surface, 1S corner portion, 1T bottom surface, 22A top surface covering part, 22B front surface covering part, 22C side surface covering part, 22D positioning convex part, 23 side wall, 23A lower side wall, 23B upper side wall, 24 notch, 25 reverse extension side wall, 25A step concave part, 26 longitudinal side wall, 27 exposure cutting part, 28 convex part, 29 gap, 30 air supply groove, 30A first air supply groove, 30B second air supply groove, 31 vertical wall, 31A bending part, 32 vertical wall, 33 rib, 34 longitudinal groove, 40 positioning connection part, 41 bottom surface connection part, 42 angle connection part, 43 convex strip, 44 concave part, 45 convex strip, 46 embedded concave part, 47 embedded convex part, 48 upright wall, 51 air supply duct, 51A inflow duct, 51B discharge duct, 52 forced air supply mechanism, 60 battery unit assembly, 62 separator, 63 covering film, 91 battery unit, 92 separator, 94 end plate, 95 connecting rod, 99 battery lamination body.

Claims

1. A power supply apparatus comprising:

a plurality of battery cells each having a thickness smaller than a width of the main surface and a square outer shape;

a separator coupled to each of the plurality of battery cells, at least partially covering a surface of the battery cell; and

a fastening member that fastens a battery laminate formed by stacking a plurality of battery cells covered with the separator in a posture in which the main surfaces face each other,

the separator is composed of an insulating member capable of elastic deformation, and,

the separator includes:

a main plate portion that covers the main surfaces of the battery cells arranged to face each other;

a box-shaped covering portion that is provided at a bottom portion of the main plate portion on the first surface side and covers the bottom surface portion of the battery cell by inserting the bottom surface portion of the battery cell into the box-shaped covering portion; and

and a corner covering portion provided on a top portion of the first surface side of the main plate portion, and covering a corner portion of the top surface portion of the battery cell.

2. The power supply device according to claim 1,

a battery cell assembly in which the separator is attached to a predetermined position of the battery cell is formed by inserting the bottom surface portion of the battery cell into the box-shaped covering portion of the separator and covering the corner portion of the top surface portion of the battery cell with the corner covering portion,

a plurality of the battery cell assemblies are stacked to form the battery stack.

3. The power supply device according to claim 1 or 2,

the partitioning member further includes a side wall that forms a side surface of the box-shaped covering portion and a side surface of the corner covering portion at a side surface of the first surface side of the main body panel portion,

a gap is formed in the middle of the side wall.

4. The power supply device according to claim 3,

the separator has a first air blowing duct formed in the first surface of the main body plate, the first air blowing duct being configured to form an air passage between the battery cells stacked on the first surface side of the main body plate and the main body plate, and to communicate openings at both ends of the first air blowing duct with the notch.

5. The power supply device according to claim 3,

the separator has a second air duct formed on a second surface of the main body panel, the second surface being a surface opposite to the first surface, the second air duct forming an air passage between the battery cells stacked on the second surface side of the main body panel and the main body panel, and openings at both ends of the second air duct being opened along the side walls.

6. The power supply device according to claim 4,

the main body plate portion is provided with a reverse extension side wall extending to the second surface side along the notch,

the reverse extension side wall is formed in a shape to be fitted into the notch of the adjacently disposed separator.

7. The power supply device according to claim 6,

the side wall includes a vertical wall in the longitudinal direction,

and the reverse elongated side wall includes vertical walls in the longitudinal direction.

8. The power supply device according to claim 7,

the fastening member includes: a pair of end plates disposed on both end surfaces of the cell stack; and

a connecting rod having both ends connected to the pair of end plates,

the tie bar includes a side panel portion that covers a side surface of the battery stack and is provided with an air blowing opening facing an opening portion of the ventilation path,

the vertical walls formed on the side walls and the reverse extension side walls are disposed at the air blowing openings.

9. The power supply device according to claim 8,

said side walls and said opposite elongated side walls comprising two rows of vertical walls in positions opposite to each other, a continuous longitudinal slot being formed by said two rows of vertical walls opposite to each other,

the connecting bar includes a connecting bar that reinforces the side panel portion in which the air blowing openings are opened, and forms the plurality of air blowing openings in the side panel portion via the connecting bar,

the connecting rod is inserted into the longitudinal groove.

10. The power supply device according to claim 1 or 2,

the power supply device further includes an insulating cover film that covers a part of the battery cells, the cover film extending at least from the surface of the battery cells covered by the box-shaped covering portion to the surface of the battery cells covered by the corner covering portions at the battery cells covered by the separators.

11. The power supply device according to claim 1 or 2,

the power supply device is disposed in a horizontal posture in which both side surfaces of the battery stack face in the vertical direction.

12. A power supply system comprising a plurality of power supply apparatuses according to any one of claims 1 to 11,

the power supply system includes at least a pair of the power supply devices, each of which is disposed in a horizontal posture in which both side surfaces of the battery stack face in the vertical direction, and the pair of power supply devices is disposed in a posture in which bottom surfaces of the battery stack face each other, and top surfaces of the battery cells face in opposite directions to each other in the horizontal direction.

13. A separator used in a power supply device in which a plurality of battery cells having a thickness smaller than the width of a main surface and a rectangular outer shape are stacked, the separator insulating the surfaces of the battery cells, the separator comprising:

a corner covering portion provided on a top portion of the first surface side of the main plate portion, covering a corner portion of the top surface portion of the battery cell,

the separator is made of an insulating member capable of elastic deformation.